---

yaml
---
r: 43082
b: refs/heads/master
c: 8542b20
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8ecb8950695e907ed25acffec9e98c6806e311c8
+refs/heads/master: 8542b200cbe5609edd7aae0c304c091a1c290452

trunk/Documentation/kernel-parameters.txt

@@ -599,8 +599,6 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	hugepages=	[HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 
-	noirqbalance	[IA-32,SMP,KNL] Disable kernel irq balancing
-
 	i8042.direct	[HW] Put keyboard port into non-translated mode
 	i8042.dumbkbd	[HW] Pretend that controller can only read data from
 			     keyboard and cannot control its state
@@ -1052,9 +1050,14 @@ and is between 256 and 4096 characters. It is defined in the file
 			in certain environments such as networked servers or
 			real-time systems.
 
+	noirqbalance	[IA-32,SMP,KNL] Disable kernel irq balancing
+
 	noirqdebug	[IA-32] Disables the code which attempts to detect and
 			disable unhandled interrupt sources.
 
+	no_timer_check	[IA-32,X86_64,APIC] Disables the code which tests for
+			broken timer IRQ sources.
+
 	noisapnp	[ISAPNP] Disables ISA PnP code.
 
 	noinitrd	[RAM] Tells the kernel not to load any configured

trunk/arch/i386/kernel/io_apic.c

@@ -1932,6 +1932,15 @@ static void __init setup_ioapic_ids_from_mpc(void)
 static void __init setup_ioapic_ids_from_mpc(void) { }
 #endif
 
+static int no_timer_check __initdata;
+
+static int __init notimercheck(char *s)
+{
+	no_timer_check = 1;
+	return 1;
+}
+__setup("no_timer_check", notimercheck);
+
 /*
  * There is a nasty bug in some older SMP boards, their mptable lies
  * about the timer IRQ. We do the following to work around the situation:
@@ -1940,10 +1949,13 @@ static void __init setup_ioapic_ids_from_mpc(void) { }
  *	- if this function detects that timer IRQs are defunct, then we fall
  *	  back to ISA timer IRQs
  */
-static int __init timer_irq_works(void)
+int __init timer_irq_works(void)
 {
 	unsigned long t1 = jiffies;
 
+	if (no_timer_check)
+		return 1;
+
 	local_irq_enable();
 	/* Let ten ticks pass... */
 	mdelay((10 * 1000) / HZ);
@@ -2214,7 +2226,7 @@ int timer_uses_ioapic_pin_0;
  * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
  * fanatically on his truly buggy board.
  */
-static inline void check_timer(void)
+static inline void __init check_timer(void)
 {
 	int apic1, pin1, apic2, pin2;
 	int vector;